A global need currently exists for additional sources of clean, renewable and affordable energy. Lack of such energy is in part responsible for global hunger and unsafe drinking water, because in many places there are adequate clean, underground water supplies, but no power for pumping the water to the surface. The lack of safe drinking water often results in polluted surface water, water-borne illnesses such as cholera and dysentery, and crop failure due to drought.
In developing countries, typical solutions to bring electricity to rural areas can include either extending the existing power grid or installing diesel generators. Both of these solutions involve high startup costs, capital outlay, and ongoing operational and maintenance expenses. For instance, extending the grid may be prohibitively expensive. Diesel generators have high startup costs and bring increased usage and transportation of fossil fuels, creating pollution as an unintended byproduct. In addition, the proper maintenance and repair of diesel generators may be beyond the abilities of the local population, leading to a dependency on the people or organization that supplied the generator.
Water power generation can be a viable alternative to extending the grid or providing diesel generators in geographic areas located adjacent a body of moving water, such as a creek, stream, or river. Water turbines can be used to harness the power of water flow to generate electricity. Deployment of water turbines, however, is typically limited to high-head, high-flow water sites, limiting the suitability of water turbines in many areas.
While high-head, high-flow water sites are relatively scarce, there are many bodies of water throughout the world that can be characterized as providing a low-head, low-flow environment. Low-head, low flow water sources are relatively abundant and can be a good source for providing power in undeveloped areas located off the grid.
For centuries, water wheels and stream wheels have been used to harness energy in low-head, low-flow environments. Improvements and developments in water wheel and stream wheel technology have been significantly reduced with the development of the water turbine. However, there is currently a renewed interest in development of water wheels and stream wheels in response to the worldwide demand for energy, especially in developing countries having areas located off the grid. There is also an interest in development of micro-hydro and pico-hydro power sources, such as less than 5 kW, for home or community use.
Thus, a need exists for an improved apparatus and method for generating electrical power from low-head, low flow water sources. An apparatus and method that uses simple technology and requires reduced training and maintenance would be particularly useful.